As is generally known, zeolites are understood to be a group of naturally occurring silicate minerals, which can also be synthetically produced mainly from sodium silicate, sodium aluminate and sodium hydroxide, which are used to a large extent in industry. A common characteristic of the crystalline structures is a three-dimensional network or matrix made of SiO.sub.4 and AlO.sub.4 tetrahedrons permeated with channels and voids. Excess negative charge loading of the matrix is compensated for by cations, e.g. Na and Ca ions. These ions can be exchanged for other ions. It is known that the suitability of zeolites as an ion exchanger is based on this. Dehydrated zeolites will absorb water in contact with surroundings containing water vapor and therefore can be used as desiccants. It is also possible to retain other, relatively small molecules, such as ammonia, hydrogen sulfide and carbon disulfide, in the voids, separating them in this way from other materials. Based on this property, zeolites can be used as so-called molecular sieves or filters.
Because of their catalytic properties, it is further known to use synthetic zeolites, in particular zeolites loaded with trivalent cations, as catalysts in the petroleum-processing industry. Methods for producing crystalline zeolites, loaded with different cations and usable as catalysts, are known, for instance from U.S. Pat. Nos. 3,702,886 and 4,250,345, British Pat. No. 1 334 243 and many other patents.